The goal of virtue inscribed in human and constitutional rights also curtails legal protection for sexuality that is not reproductive. If rights are essentially natural law, and natural law is another word for the will of God, then rights must sponsor virtue. When the matter at hand is sex, the question is: what kind of sex is virtuous? After centuries of controversy, the Catholic church concluded that only reproductive sex within marriage can be virtuous. Since God mandated humans to reproduce (“go forth and be fruitful”), reproductive sex is in fact a core element of God ’ s plan for humankind, and therefore a common human good. But other forms and expressions of sexuality, such as sex without vaginal intercourse, same-sex relations, and sex outside of marriage are not. Rights cannot protect these choices because rights cannot contradict natural law; they are not legitimate exercises of freedom. Incidentally neither is contraception (God wants us to reproduce) nor assisted reproduction (but only naturally).
The Catholic understanding of sex as essentially procreative is intimately related to a particular understanding of sexual difference of profound theological importance. Men and women are essentially different beings, whose differences, determined by nature, hinge on women ’ s singularity: women ’ s essence is defined as loving and giving, while male essence is not explicitly defi ned qua male. The purpose of women ’ s life, their dignity, lies in the realization of this essence by existing “for the other.” This must not be confused with male domination—a direct result of original sin and not of God ’ s will. Before the Fall, mutuality or reciprocity existed between male and female, as both man and woman existed “for the other.” But God ’ s punishment for sin was different for each sex, and in women ’ s case it included male domination. As a consequence, redemption for women is deeply connected to the fulfi llment of the call to motherhood and family life in service and sacrifice. Traditional gender roles are thus linked to salvation. This explains why the Vatican systematically argues that feminist theories and politics misunderstand natural gender roles. For the church sexual difference entails gendered roles which are not cultural, and instead part of the salvational narrative.
This understanding of sexual difference explains the attachment to and defense of lifelong heterosexual marriage, the rejection of homosexuality, the negative views on non-procreative sexuality, and the defense of traditional gender roles. These are all issues that the Catholic church considers non-negotiable, issues which the faithful must oppose through legal and political activism.
Source: Julieta Lemaitre “By reason alone: Catholicism, constitutions, and sex in the Americas” Int J Constitutional Law (2012) 10(2): 493-51